Recirculation insulated space heater



Nov. Z0, i945. A. P. LNAR RECIRCULATION INSULATED SPACE HEATER Filed April 17, 1943 INVENTOR ffm Patented Nov. 20, 1945 UNITED STATES 2,389,265 RECIRCULATION INSULATED SPACE HEATER Allen P. Lvar, Dayton, Ohio, assignor to Chrysler Corporation, Highla tion of Delaware nd Park, Mich., acorpora- AApplication April 17, 1943, Serial No. 483,469

l Claims.

This invention relates to space heaters, and it has particular reference to the provision of an insulating medium for such a heater consisting es- 'are applicable to various installations, including the heating of small homes, or the heating of limited portions of larger dwellings. Some of these installations, however, give rise to an insulating problem,-and the present invention is concerned with an effective solution thereof.

As `illustrative of the problem, it may be observed that space heaters of the class described are frequently installed in what are called utility closets', where there is very little Vspace between the exterior'- wall of the heater and the building or closet wallsitself. Excessive heat losses through the-iurnace`casing thereby add to a potentialre hazard,f particularly when housewives use the closet'J-forl'the storage of cloths saturated with furnitureoil Again, these units iind application inba'semntsconverted into what are known as recreationvorfrumpus `roornsffHere; there is no serious'rehazarddueto close confinement, but people are. prone to bumplinto the outer walls andi-Thurn themselves, and a high exterior temperature-alsoprecludes decorative nishes which are'fdesirable for installationsfof lthis nature. An ob'vious expedient is, of course,fto insulate the heaterwall, 'eithei interiorIy-iorexteriorly, with thfcustoma'r'y forms of ffsheet' insulation materia'l lI-Iowev'er,'fthisfislnot af'satis'factory solution nifl-the probleinfdue, among other" things, to the 'iincreas'ef in Awefl'ghtf and expense and I nevertheless a' `residual heat loss. According to thepr'esentfi 'iit'iom the known forni :space heater 'is-'jal'seted by means of an exterior'f'casing and thef'clda-irwhich is to be heated is made to circulate between the jacket and'thecasing for the hea rp'r? I have discof'vredithat it is not ncessaryto make all of the col ',f'on the contrary,

site aregiiararatai wherein:

Fig. 1 is a frontal view, with parts of the casof'the total voly A. a well 'designed 'svurface tempera F50 noted that the jacket il extends below thedeck l ill" ings broken away, illustrating my invention as vapplied to a heater Vof the type shown in my stated patent.

Fig. 2 is a side elevational view of the same unit ith parts of the casings broken away; and

Fig. 3 is a section taken substantially along the line 3--3 of Fig. 2.

In common with the' disclosure of my Patent No. 2,196,703, there is shown in the drawing a heater having an inner casing wall l0 composed of a top ll, and four side walls l2 which are joined at their bottoms by a deck I3. Suspended from the deck i3 is a blower unit consisting of a pair of casings I4 and containing rotors driven .15 by a motor l5 in order to aspirate air through an inlet I6 for delivery to the casing, above the deck, through outlets l'l communicating with apertures formed in the deck itself. The casing l0 moreover contains a re box I8 and a pair of heat interchangersl I9 which are m'ounted on crossbars 2l below the top H and above the deck I3.

As more fully described in the prior patent, the

fire box I8 contains a burner 22 adapted to receive a mixture of combustible fuel and air through an inlet coupling 23 which extends'exteriorly of the casing and through one of the walls thereof. The hot products of combustion flow upwardly within the box la, and pass through ilues 2d into the heat interchangers I9. The heat interchangers E9 include baffle plates 25 causing the hot gases to circulate therethrough, and eventually to flow into a manifold 26 communicating with a stack coupling 2l. f

constitutes a plenum chamber 28, wherein the blower discharge is initially received, for circulation through the various passage ways 3l, 92, 3ft, etc. for circulation around the re box and the heat interchangers. The cold air in the chamber 28 is accordingly heated, and rises to the overhead space 35 for delivery to a discharge line d3 which are disposed parallel to and spaced from the comparable walls of the casing. It will be i3 to form a blower compartment dll housing the blower lil, and provided with a cold air inlet d5. This inlet may be connected to any suitable point for discharge through the lines 3l.

The space between the deck i3 and the rails 2l teror jacket il having a, top wall l2 and side walls ing through the opening 45.

Referring particularly to Fig. 3, it will be seen that the casing walls l2 are formed of sheet metal plates, whose edges are ilared outwardly at about a 45 angle to provide corner portions 46 which abut each other and extend to the corners between the side walls 43 oi' the jacket 4i. The plates I2 may be welded to each other along the edges 46, and the parts may be so dimensioned that the projecting corners of the casing -ilt snugly within the jacket 43, thereby facilitating the Aassembling and mounting of the casing within the jacket. Any additional desired means of mounting the casing within the jacket may, of course, be employed. This construction accordingly divides the free space between the jacket and the casing into a plurality of vertically disposed compartments 41, 48, etc. All of these compartments freely communicate with the overhead clear space between the tops Il and 42, which forms an additional compartment 49.

Certain of the casing walls i2, adjacent the plenum chamber 28, are formed with a number of apertures 5l, which permit air passing through the blowers to be diverted in part to the compartments formed betweenthe jacket and casing walls. Each such compartment is sealed from the blower chamber 44 by a sealing strip 52 which extends transversely of the unit and between the walls I2 and 43. In practice, the size and number of the apertures should be so chosen that not all of the air will freely enter these compartments, about 5 or 10% being adequate for the present purposes. As best shown in Fig. 2, the compartment 48 is not provided with a sealing strip 52, and it is therefore, in free communication with the inlet I6 of the blower i4. The casing wall i2 dening the inner portion of the compartment 48 lmanner heretofore described, for delivery to the space to be heated. A minor portion of the delivered cold air iiows however, through the openings 5| into the several compartments 41. This cold air absorbs whatever heat may be transferred through the walls i2 of the casing i0, and it then flows upwardly into the upper compartment 49, and thence downwardly through the compartment 48, and so back into the blower i4.

. It will bel seen that this fraction of the total air volume is, therefore, re-circulated around the casing I0 of the heater, and its volume is suicient to prevent the outer walls 42 and 43 of the jacket 4i from reaching a temperature resulting in any fire hazard, or causing discoloration and deterioration of any decorative finish placed thereon. The heat content of the re-circulated air is, of course, returned to the main heating circuit by admixture with sufficient cold air enter- Accordingly, the heat exchange properties of the entire unit are enhanced, its safety factor is increased, and the unit is more readily applicable to Various installations than the heater described in my prior patent.

While I have described my invention with reference to,one specic embodiment thereof, and have referred to a known type of space heater in order to illustrate its principles, it will be apparcasing, a heater in -the casing, passageways formed 4 .sheet metal inner casing formed of plates joined together, the corners of said casing being bent outwardly and lengaging the inner wall of the jacket to space the casing from the jacket and to form a. plurality of compartments therebetween,y said casing being spaced from the top of the jacket and terminating above the bottom thereof, a deck at the bottom of the casing, a, blower mounted within the jacket under said deck, the discharge opening of the blower communicating with .the casing, apertures formed in certain of said plates adjacent the deck for admitting a minor portion of the air delivered by the blower to some of the compartments defined by said plates and corners, means sealing the lower ends of such compartments from said under-deck portion of the jacket and thereby the inlet of the blower, all of said compartments communicating at the top of the casing, at least one of said compartments freely communicating with the lower portion of the jacket and said blower inlet, said last named compartment being sealed from the interior of the casing, and means in said casing for heating the major portion of Ithe air delivered by the blower and the air recirculated through said compartments.

2. A space heater comprising a top, side walls. and a lower deck, a. blower mounted below the deck and having its outlet discharging into lthe in the casing for passing theair delivered by the blower in heat exchange relation to the heater, a warm air outlet formed in the top of the casing, a jacket having a' topy and side walls disposed over the casing and extending below the deck to house the blower, a cold air inlet in the lower portion of the jacket communicating with -the inlet of the blower, said jacket and casingbeing spaced from each other at said top and side walls, spacer plates extending from the side walls of the casing to the side walls of the jacket to divide the space therebetween into a plurality of vertical compartments communicating with the space between the tops, apertures formed in certain of the casing side walls, adjacent the deck to admit a portion of the air passing the blower to certain of said compartments, sealing bars at the bottom of some of said vertical compartments to isolate the same from the blower inlet, at least one of said vertical compartments being free from such apertures and freely communicating at its bottom with the blower inlet, said warm air outlet extending through the top of .the jacket, whereby a portion of the cold air delivered-by the blower is recirculated around the casing and through the com partments to insulate the outer jacket from heat losses.

3. A space heater comprising a casing having side and top walls and containing a fire box, an

exterior jacket surrounding the casing havingv having apertures in the side wall thereof between said re box and said blower compartment cornmunicating with at least one of said plurality of compartments for diverting thereto a portion of the air delivered to said casing by said blower, another of said plurality of compartments being sealed with respect to the interior oi the casing and communicating with the space between the casing and jacket top Walls and with said blower compartment for returning to the latter that portion of the air sodiverted as aforesaid.

4. A space heater comprising an inner casing having top and side walls, a burner in the irmer casing, duct means in said casing for conveying lwaste gases to a ue, a bottom deck for said casing formed with an air vent, a blower having its outlet i connected to fthe vent to supply air to be heated formed with a warm air opening adjacent the top thereof, an exterior Jacket around the inner casing have top and side walls spaced from the top and side walls respectively of the casing, partitions dividing the space between the casing and jacket side walls into a, plurality of vertical compartments each communicating with the space between the casing and jacket top walls, said casing being formed adjacent said vent -with apertures admitting air delivered by the blower to certain of said vertical compartments, another of said vertical com-partments being in open communication with the inlet of the blower for returning air circulated through said compartments to said blower.

ALLEN P. LIVAR. 

